package com.starry.FileUpload;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.File;
import java.io.IOException;
import java.util.List;

public class UploadServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    // 上传文件存储目录
    private static final String BaseSavePath = "e://fileDownload";

    // 上传配置
    private static final int MEMORY_THRESHOLD   = 1024 * 1024 * 3;  // 3MB
    private static final int MAX_FILE_SIZE      = 1024 * 1024 * 40; // 40MB
    private static final int MAX_REQUEST_SIZE   = 1024 * 1024 * 50; // 50MB


    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("uploading...");
        if(!ServletFileUpload.isMultipartContent(request)){
            System.out.println("上传请求类型错误...");
            return;
        }
        DiskFileItemFactory factory = new DiskFileItemFactory();
        factory.setSizeThreshold(MEMORY_THRESHOLD);
        ServletFileUpload upload = new ServletFileUpload(factory);
        // 设置最大文件上传值
        upload.setFileSizeMax(MAX_FILE_SIZE);
        // 设置最大请求值 (包含文件和表单数据)
        upload.setSizeMax(MAX_REQUEST_SIZE);
        // 中文处理
        upload.setHeaderEncoding("UTF-8");
        // 如果目录不存在则创建
        File uploadDir = new File(BaseSavePath);
        if (!uploadDir.exists()) {
            uploadDir.mkdir();
        }
        try {
            List<FileItem> formItems = upload.parseRequest(request);

            if (formItems != null && formItems.size() > 0) {
                // 迭代表单数据
                for (FileItem item : formItems) {
                    // 处理不在表单中的字段
                    if (item.isFormField()) {
                        System.out.println("key="+ item.getFieldName());
                        System.out.println("value="+ item.getString("UTF-8"));
                    }
                    else {
                        String fileName = item.getFieldName()+"_"+item.getName();
                        String filePath = BaseSavePath + File.separator + fileName;
                        File storeFile = new File(filePath);

                        // 在控制台输出文件的上传路径
                        System.out.println(filePath);
                        // 保存文件到硬盘
                        item.write(storeFile);
                        request.setAttribute("message",
                                "文件上传成功!");
                    }
                }
            }
        } catch (Exception ex) {
            request.setAttribute("message",
                    "错误信息: " + ex.getMessage());
        }
    }
}
